The invention relates to a clutch device (also called a modular system comprising a clutch (friction clutch/friction coupling) and clutch actuator) for a drivetrain of a motor vehicle, for example a passenger vehicle, truck, bus, or an agricultural utility vehicle, comprising a pressure plate displaceable in the axial direction of the clutch device, with the pressure plate, in a coupled position of the clutch device, pressing a clutch disk against a counterpressure plate that can be connected to a crankshaft of an internal combustion engine, and comprising an actuating device having a displaceable actuating piston, with the displacement position of the actuating piston determining the position of the pressure plate and allowing that the actuating piston to be driven by a drive unit of the actuating device between a coupled position and a decoupled position in order to displace the pressure plate.
Respective clutch devices/clutch systems are known from prior art. For example, DE 10 2005 014 633 A1 discloses a clutch and a clutch actuator as well as a method for actuating at least one clutch in a drivetrain of a motor vehicle. The clutch actuator comprises an electromotive actuating drive and a disengagement arrangement, by which a rotary motion of the actuator drive can be converted into a translational disengagement motion of a releasing device for moving the clutch, with the releasing device (disengaging arrangement) comprising a belt drive having an outer part and an inner part, and the actuator drive being formed for the releasing device of an electric motor, with the outer part of the belt drive being coupled to the crankshaft of the internal combustion engine and the inner part of the belt drive to the rotor of the electric motor.
However, clutch systems of prior art are preferably based on an electromotive actuation, with the actuating energy required for moving/adjusting the actuating piston being generated in an electromotive fashion. Additionally, the clutch systems of prior art comprises the actuator assembled from several individual components, which are only completely combined by the initial manufacturer (OEM/Original Equipment Manufacturer).
Furthermore, electronic clutches are also known, with small electric motors being positioned in the clutch/clutch device, which actuate the clutch via ramps and the booster function connected thereto. For this electromotive generation of the actuating energy however, initially relatively costly motors and their control electronics are required. Furthermore, the energy for these motors is initially taken via the alternator from the drivetrain, saved in the battery, and then tapped from there. The energy required for actuating the clutch is here initially converted expensively into electric energy via the generators or external pumps in the drivetrain. Here, major loss occurs and all components of this chain must be sized appropriately large. Additionally, it may occur that the motors are embodied too weak, due to the limited space available. Although the motors may fit inside the clutch, however in this dimension they are too weak for actuating. Accordingly, in this context commonly a booster function with ramps is used in order to generate the actuating force. However this may lead perhaps to grabbing problems and the risk develops that the clutch jams when the friction values become excessive. Additionally, these so-called booster clutches, which tap energy from the drive train, also show problems with cyclic nonconformity. Under certain circumstances, this leads to instability of the clutch torque. Furthermore these clutch systems have the disadvantage that they are frequently only assembled at the customer (OEM), resulting in potential errors during the assembly/the complete assembly being relatively high. Even if all components were previously tested, problems may still arise which can occur only during the assembly with the other OEM-parts.